Combine vinegar, wine, shallots, and peppercorns in a small saucepan. Bring to a boil. Reduce heat to a simmer and cook for 5 minutes. At this point you should have about 3 tablespoons of mixture. Strain mixture and discard solids. Set liquid aside to cool. Combine egg yolks with the cooled liquid in the top of a double boiler. Place over simmering water. Cook while whisking for 5 minutes. Remove from heat. Whisk in butter 2 tablespoons at a time. Make sure butter is melted and whisked in before adding more. Stir in tarragon, salt and peppers. This is normally served over beef but can also be used as a sauce for vegetables, eggs, or seafood.